AN ALGORITHMIC APPROACH TO CHRONIC COUGH

Objectives: To evaluate a stepwise approach to chronic cough that emph asized initial treatment of all patients with an antihistamine-deconge stant for postnasal drip and to determine the value of routine broncho provocation challenge in the evaluation of chronic cough. Design: Pros pective trial using an algorithm for chronic cough in immunocompetent nonsmoking outpatients. Setting: University-based pulmonary practice. Patients: Forty-five patients met the inclusion criteria. The mean dur ation of cough was 140 weeks (range, 3 to 2080 weeks), and the mean se verity of cough as assessed by patients on a four-point scale was ''se vere.'' Results: Marked improvement and resolution (mean, 3.1 and 7.1 weeks, respectively), with resolution in 96% of patients. Antihistamin e-decongestant therapy was beneficial in 39 of 45 patients and was the only therapy needed for 16 patients. Bronchoprovocation challenge had a negative predictive value of 100% and a positive predictive value o f 74% for cough caused by asthma. No significant relationship was foun d between the time to cough resolution and duration or severity of cou gh. Eighteen percent of patients experienced a recurrence of cough at a follow-up interval of 3 months. Conclusions: A sequential approach t o chronic cough that emphasizes initial treatment with an antihistamin e-decongestant is effective. Bronchoprovocation challenge is useful in evaluating patients with chronic cough but can be delayed until the i nitial response to antihistamine-decongestant therapy has been assesse d. The 18% incidence of recurrence highlights the fact that cough ofte n is the manifestation of a chronic or recurring process that requires chronic or episodic therapy.